Location

Our study of coastal erosion centers around the Gulf Coast of the United States in reference to the states that border the Gulf of Mexico: Texas, Louisiana, Mississippi, Alabama, and Florida.  



Coastal erosion is a growing issue that affects a high percentage of the world's population, as coastlines are an overwhelmingly popular place to live. In the US, coastal counties contain 25% of the country's population. 

In addition to the Gulf Coast US, coastal erosion evolved into a worldwide concern in coastal areas and islands as sea levels rise with the increase of carbon dioxide in the atmosphere contributing to global warming climate change. It takes place in many forms over many different types of ecosystems, including intertidal zones, sand beaches, mud flats, barrier islands, marshes, and deltas, especially biomes with fine-grained sediments that can easily be eroded in the case of coastal storms such as the hurricanes that so often hit the Gulf Coast. Below shows how Florida would be affected if sea level rose by 1 meter. 

The Gulf of Mexico's warm waters, the fine-grained sediments of the coastline, and the overwhelming and growing anthropogenic development of the coastline leave Texas, Louisiana, Alabama, Mississippi, and Florida vulnerable to coastal erosion and all of the myriad problems that come with it. Also, these areas have low oceanic energy and a relatively small tidal range, which is correlated with high levels of erosion. In Texas, almost half of the sand from updraft erosion has been trapped by jetties at harbor entrances, an example of erosion moving sediment to less desired areas. In general in Texas, the length of eroding coast and rate of erosion has substantially increased since the 1950s. Social characteristics are also important in this area, as coastlines are vulnerable due to human activity around these environments. 

Studies within the Gulf Coast area have shown that changes in sea level tied to coastal erosion are greatest around New Orleans, Louisiana, which can reach up to 10 mm/year. East of New Orleans the rise is about 2 mm/year. West of Louisiana is in the 3-5 mm/year range; all considered very high risk. These high erosion rates are due to the "natural compaction of the Holocene deltaic sediments in the Gulf of Mexico", the natural geologic risk factor that gives the Gulf Coast the topographic features that put it at risk for coastal erosion (Erosion Hazard Vulnerability). Areas with higher coastal slope, such as the Florida Panhandle, are at lower risk than lower lying places like New Orleans and the Texas coast, which also experiences higher mean wave height. 

Specifics of the Problem

By definition, coastal erosion is the loss of shoreline, beach, and/or dune sediments caused by lack of sediment delivered to the coast to balance out the impacts ranging from man-made actions like the damming of rivers, land subsidence from groundwater withdrawal, construction of seawalls, groins and jetties, diversion of rivers and streams, boat wakes and other factors as well as natural processes like storm waves, tidal surges, high winds, and loss of wetlands.

As human settlements and modifications of coastal regions have intensified, so have the problems with coastal erosion. For example, in many Gulf Coast areas such as central Florida, barrier islands like mangrove forests are reduced and homes and businesses are built on top of these inter coastal areas. Also, humans move around sediment and modify coastlines in order to create shipping channels and more space for homes. This also leaves human settlements at risk for natural disaster when hurricanes come through, such as the Katrina tragedy in 2005. 

Several factors determine risk for coastal erosion. Studies have found that tidal range and rate of relative sea level rise are highly significant, which will become an increasingly serious issue as sea level rises with climate change. Speculations about rise in global sea level range between 15-95 cm by 2100. Other important factors include geomorphology, coastal slope gradient, shoreline erosion acceleration rates, and mean wave height (Erosion Hazard Vulnerability Study). This study concludes that long-term decisions to renourish or engineer a coastline may be the single determining factor in how that particular coastal settlement evolves. 

As mentioned above, anthropogenic effects are also important, though not noted in this study. Humans often alter coastline for their own personal use, leaving themselves vulnerable to all of the risks noted above. 

The consequences that will arise from Coastal erosion are that people and ecosystems will be greatly affected. It affects the environment because wetlands and coasts are being destroyed by sediment depletion and storms. Without the sediment that usually contains minerals that the plant life need, they start to disappear. Many marshes become converted to open-water bodies, which can undergo a complete transformation in less than 40 years, showing the immediate gravity of this issue. 

Undoubtedly, great consequences will arise from coastal erosion as people and ecosystems will be increasingly affected. This growing problem affects the environment because wetlands and coasts are being destroyed by sediment depletion and storms. Without the sediment that usually contains minerals that the plant life need, gradually aquatic and semiaquatic plant life like mangroves and sea oats will start to disappear. 

Other coastal wildlife is affected as well; animals such as birds, fish and deer that live up and down the coastline. As the land retreats, the deer will be forced to move closer to more densely populated areas. Additionally, many species of fish use the wetlands as nurseries, and birds use this area to nest repopulate as well. Coastal erosion affects these populations because many of these species rely on the coastline ecosystem at their various stages of life, as well as people who live near the coast. This erosion losing the wetlands will greatly affect humans socially and economically because these states near The Gulf, especially Louisiana (which provides 30% of the nations fish), rely on the population of fish for income. With decreased aquatic habitat, the Gulf of Mexico's fishing industry will suffer. Therefore as these wetlands disappear, the fish population lowers, the fish industry is hit by hard times, and the economy becomes affected. There will be loss of jobs and prices for fish will rise. 

One of the co-writers of this blog, Bailey Rosen, undertook her own research on coastal erosion by investigating the presence of coquina shells, an indicator of intertidal zone health, at increasing distances away from coastal erosion reconstruction projects on the St. Petersburg beaches on the Gulf Coast of central Florida. The results showed that there were no coquinas found on Upham or St. Pete Beaches where coastal erosion was having great effects on the ecosystem and restoration practices (huge sand bags below) were underway. The further away from the erosion and restoration, the more coquinas found, indicating a healthier ecosystem. 

Table 3.2 – T Test using data from Table 3.0

Null Hypothesis: There is no statistical difference between the amount of coquina clams in each location. 

	St. Pete Beach	Upham Beach	Madeira Beach	Redington Beach
	0	0	173	498
	0	0	208	236	0.174677388
	0	0	191	742
N=	3	3	3	3
Average=	0	0	191	492
StDev=	0	0	14	207

Larger Consequences

There are definitely other places around the world with the same problem regarding coastal erosion. Places such as Southern California, Britain, and Australia are affected by this growing phenomenon. The same consequences that occur in the Gulf Coast of the United States due to coastal erosion can be seen the same around the world. In Southern California man-made structures such as jetties, seawalls, etc. deprave our beaches from getting the crucial wave action that the beach needs. Furthermore, in order to protect more property, dams were built in the mountains to hold back a lot of sediment that is originally supposed to replenish the sand on the beaches. Because of these structures, this has made our coastline much more vulnerable to storms. Additionally, in order to uphold the attraction of the beaches, thousands are spent in “nourishing” the beaches every year, by putting 3 Rose Bowls worth of sand on our beaches.

 In Britain, specifically East Sussex, there is also plentiful evidence of coastal erosion. Although these pictures of the cottages in the Birling Gap were taken more than one hundred years apart, in recent years coastal erosion has quickened. The three meters that should have eroded in a span of seven years, eroded within four months. This was due to terrible winter storms that people were not expecting. This poses as a danger to civilians as property can fall or crumbling rock can injure people. 

In Queensland, Australia there is a major coastal erosion problem affecting the city of Cairns. Again, due to man-made structures in this case seawalls, the wildlife and population will be negatively affected because the plant and wildlife are receding or disappearing and the inland area will take more damage during a tropical storm. 

The impacts of coastal erosion on the Gulf Coast are essentially the same around the world, though as noted above, the Gulf has certain characteristics that make it far more vulnerable. In places with cliffs and less infrastructure surrounding the area, consequences will be less severe. Due to coastal erosion, urban infrastructure and economies worldwide will suffer. Many places around the world rely on beaches for tourism as well. Moreover, much of the population lives near the coastline; there will be a lot of money spent on repairing damage to property from storms or from moving property further inland. There is great speculation that the latter is the best way to spend the money. Furthermore the people working for the fish industry will be negatively affected as populations of fish diminish. As sea levels continue to rise in tandem with coastal erosion, more and more homes, businesses, and ecosystems will face the oceans and seas on their doorsteps. 

Solutions

Some potential solutions for coastal erosion is building structures such as Groins, Jetties, and Seawalls. A non-structural solution for coastal erosion is beach nourishment, which is the process of dumping sand from somewhere else onto a beach to widen the area. It is important to keep in mind that there are advantages and disadvantages to these solutions.

Groins

·      Retain sandy beaches and does not affect access to beach

·      The sand being trapped at one beach may be helping but this will also cause another beach to “starve”. Meaning there is no sand to be trapped because of the beach before.

·      Needs to be replaced every 15-20 years

·      The structure does not cost much

Jetties

·      Avoid build up of unwanted sediments by collecting sand on one side

·      The opposite side not obtaining the sand the will erode and narrow the beach

Seawalls

·      Provide defense where wave energy is high

·      Expensive

o   In Cape Coral, it was around $10,000 for a 80ft wide frontage

·      Can affect peoples access to the beach

·      Recurved seawalls can increase erosion

Beach Nourishment

·      This process does not stop coastal erosion, but gives us time

·      Expensive

o   Miami holds the record at paying $17.5 million per mile

·      This process requires a lot of construction over a long period of time      The replacement methods and sediment used differ from than the usual sand, which can have affects such as changing the shape of the beach. It can also erode faster--studies have shown that "all biological variables [of the ecosystem] showed a significant decrease immediately after dredging"

Building these structures are not the only way we can prevent coastal erosion. Organizations can help by conducting programs and projects to prevent coastal erosion and they also educate communities that this is a serious problem. Three organizations that handle this issue are:

Coastal States Organization

·      They work with Congress to help them look over proposed regulations that could improve coastal problems

·      Advocate for more funding and support for other ocean and coastal programs

The Coastal Protection and Restoration Authority

·      Coastal programs

·      Berm to barrier

o   After oil spill in 2010, CPRA set up barrier islands to protect against storm surge and ecosystem degradation

·      Projects

Americas Wetland foundation

·      Their focus is to bring attention the importance of wetlands and coastal concerns for the Gulf coast

·      Projects

o   Americas Energy coast

§  Incorporates major businesses and industries, organizations, researchers and scientists to provide the public with knowledge and information

In Conclusion...

Understand that the environment is constantly changing and that our actions from coastal development, to habitat destruction, to building dams and dredging can gravely affect the environment that we build our homes and communities on. Therefore it is crucial for companies that have or want to build more structures to put more research into the effects the structure has on the environment not just locally but regionally. The next step is to build and implement better solutions. This can be enforced by us, the community, as we should become more informed and politically involved to make sure that laws be amended or passed in order to help our environment. We should not only learn from our past mistakes but also correct them. As global climate change and coastal development continue, it is important that we as a local and global community use mitigation and adaptation techniques in order to best prevent and handle potential downfalls of coastal erosion.

This will become increasingly important because the problem of coastal erosion will not be going away any time soon. As human populations continue to rise and people flock to the coast, the problem will worsen as the natural mechanisms of coastline defense are increasingly worn down. That compounded with rising sea levels creates a huge potential problem. It is important for people to become educated and recognize the impending threat our coasts face, and come together to prevent disaster from occurring in the future.

Thank you for your attention!!

Sources

Works Cited

"AAPG Datapages/Archives." : Relationships among Vertical Accretion, Coastal Submergence, and Erosion in a Louisiana Gulf Coast Marsh. N.p., n.d. Web. 13 Mar. 2015.

"AAPG Datapages/Archives." : Temporal and Spatial Variations in Shoreline Changes and Their Implications, Examples from the Texas Gulf Coast. N.p., n.d. Web. 13 Mar. 2015.

"California Coastal Commission Climate Change Resources." California Coastal Commission Climate Change Resources. N.p., n.d. Web. 08 Mar. 2015.

"Coastal Erosion." Coastal Erosion. N.p., n.d. Web. 13 Mar. 2015.

"Download PDFs." Clam Dredging Effects and Subsequent Recovery of Benthic Communities at Different Depth Ranges. N.p., n.d. Web. 13 Mar. 2015.

"Erosion Hazard Vulnerability of US Coastal Counties." Journal of Coastal Research Online. N.p., n.d. Web. 13 Mar. 2015.

"INTRODUCTION." Coastal Vulnerability to Sea-Level Rise:. N.p., n.d. Web. 13 Mar. 2015.

"Louisiana's Oil." Wetlands and Coastal Erosion. N.p., n.d. Web. 08 Mar. 2015.

"MEDIA NOLA." Coastal Erosion of the Gulf Coast and Its Effects in the Region @ Media Nola. N.p., 04 May 2014. Web. 08 Mar. 2015.

Peterson, Molly. "'Beach Nourishment' Fights Human-caused Erosion of LA Beaches." Southern California Public Radio. N.p., 10 July 2013. Web. 08 Mar. 2015.

Short, Andrew. "Impact of Coastal Erosion in Australia." Coastalwatch.com. Media Nola, 08 Nov. 2008. Web. 07 Mar. 2015.

Spillett, Richard. "Britain's Vanishing Coastline: Amazing Before-and-after Pictures Taken a Century Apart Reveal How Quickly Parts of the UK Are Disappearing into the Sea." Mail Online. Associated Newspapers, 08 Apr. 2014. Web. 08 Mar. 2015.
Coastal Care. "Shoreline Engineering" Retrieved from http://coastalcare.org/educate/shoreline-engineering/#groins-jetties
Williams, S. J. (2001). "Coastal Erosion and Land Loss Around the United States: Strategies to Manage and Protect Coastal Resource- Examples from Louisiana". http://www.fws.gov/nc-es/ecoconf/williams%20paper.pdf